Day-58 Java Basics: Static, Non-Static, Objects, Methods, Return Types

Static and Non-Static

In Java, static is used when something belongs to the class itself. It is common for all objects. Non-static is used when something belongs to a particular object. It is different for each object created from the class.

Example:

public class Home { // non-static: object specific information String name1 = "dhanush"; int age1 = 25; // static: class specific information static String name2 = "tamil"; static int age2 = 15; public static void main(String[] ramesh) { System.out.println(Home.name2); System.out.println(Home.age2); Home person = new Home(); // new object System.out.println(person.name1); System.out.println(person.age1); } } 

Objects

An object is created from a class using the new keyword. It creates space in memory to store data and methods defined in the class.

Example:

Home person = new Home(); 

Methods

Methods are sets of instructions grouped together with a name. They are used to perform specific tasks. Methods can be reused and called again whenever needed.

Example:

public class Shop { static String shopName = "seenu"; String product_name = "pen"; int product_price = 10; public static void main(String[] args) { Shop product = new Shop(); // method calling statement  String greeting = product.buy(); System.out.println(greeting); } String buy() { System.out.println("buy method"); return "thank you"; } } 

Return Types

Methods have return types. If a method does not return anything, we use void in its declaration. If a method returns something, we mention its datatype. The return keyword is used to send back a value from the method, which can be stored in a variable for later use.

In the above example:

• The buy() method returns a String value "thank you".
• The returned value is stored in the variable greeting.